Quance Dominates Competition but Falls Short of Nall’s Mark : Swimming: Northridge teen-ager wins national title in 200-meter breaststroke but fails to match Olympic medalist’s time.

Kristine Quance’s chief American rival wasn’t even in the pool Tuesday, but she was in Quance’s thoughts every stroke of the 200-meter breaststroke in the U.S. Swimming National Championships at Mission Viejo.

A bout with mononucleosis cost Quance a chance at earning a berth on the U.S. Olympic team, so her goal entering Tuesday’s competition was to better the time Anita Nall had recorded in winning the bronze medal in Barcelona.

Quance came up 0.97 seconds short but still bettered a 10-year-old pool record with a time of 2 minutes 27.84 seconds--5.33 seconds ahead of runner-up Rachel Gustin.

After touching the wall Quance, a 17-year-old from Northridge, floated onto her back to get a clear look at the scoreboard where the competitors’ times were posted.

“I thought, ‘Oh, my gosh, it’s over,’ ” Quance said. “I was a little disappointed and I was happy all at the same time.”

Although she failed to match Nall’s Olympic effort--accounting for her disappointment--the time would have placed her fourth at Barcelona. It also was the second fastest of her career. Quance’s coach, Bud McAllister of Calabasas-based CLASS Aquatics, was duly impressed.

“She’s really tough mentally,” he said.

So is Quance’s teammate, Alexis Larsen, 15, who finished only 0.66 seconds behind winner Sarah Anderson, 17, in the 800 freestyle.

In the last 50 meters, Larsen gamely tried to make up the gap.

“I tried,” Larsen said. “I went as fast as I could. (Anderson) probably had more left because she went out a little slower.”

Larsen’s time of 8:41.02 was seven seconds faster than her previous best.

“I’m happy with that,” McAllister said. “I wasn’t sure how she would do. Her freestyle training has not been as strong, but her IM (individual medley) training has been great. It carried her through.”

In the men’s 800 freestyle, Ben Swartout, 18, of the Buenaventura Swim Club placed eighth in 8:14.56, a lifetime best by 5.5 seconds.

Jason Stelle, 19, of Westlake Village also turned in a personal best with his ninth-place finish in the 200 backstroke in 2:03.01.

Lindsay Gassner, 16, of Canyons Aquatics placed 16th in the 100 freestyle with a 59.24. Gassner swam faster in the morning preliminaries, touching in 58.14.

Two swimmers made memorable debuts in their first national championships. Chris Pelant, 16, of Buenaventura finished 17th in the 200 butterfly in 2:03.66 and teammate Mandy Walz, 15, placed 45th in the 200 backstroke with a 2:22.25.